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Avoid duplicate text. My understanding of best practice here would be to have unique content and intent to the meta description. Intent since this is encouraging engagement more than just describing the product.

What happens if you don't enter a meta description? If your product pages are really thin on content then Google may have difficultly scraping its own meta description. However, you've mentioned that prioduct descriptions are already optimised so hopefully that includes being rich and Google can create its own descriptions.

How could you create meta descriptions without bespoke copy? Two programmatic approaches to the meta tags come to mind. 1.) Scrape you own product descriptions as you suggest or 2.) create a template meta tag with variables for product name, category, etc , perhaps some randomised part sentences if you're feeling adventurous. Both approaches are going to look a little redundant/duplicate to Google however.

In my opinion, if you can't create bespoke meta descriptions, you might be best leaving it blank.

Short answer; I think you  can get more value from an H1 tag, so its a small SEO issue.

However, it really depends what image you're talking about. Is this just a logo? If so it doesn't adequately describe page content in a way that people or search engines can understand. Regardless, putting that image in an H1 tag does nothing for the image.

H tags should display a hierarchy. As James mentions above, H1 tags should contain an editorial description of the page; a headline, this is best for usability (which trickles down to SEO impact).

Anecdotally I've found keywords in H1 tags to have greater sway over page relevance than keywords in body copy. They are certainly one of the areas I pay more attention to. Despite that, it's not unusual to find logos in H1 tags, especially on homepages. But I'd encourage you to consider putting that H1 tag around a keyword optimised mission statement/heading on your homepage instead. The logo can remain visually as prominent. Ranking for your companies name is rarely hard so why have the code focus on that?

What about standards? Well interstingly w3c uses img in an H1 tag. With an alt tag of "w3c". That will be machine readable, but not very helpful as a page heading. Then again w3c goes on to use h1 tag for its page titles as well thus committing the sin of multiple H1 tags. Only thing of relevance they say is that you can include HTML in an H1 tag, so one option is an image and text.

In summary;

• one H1 tag per page
• the right place in the hierarchy (with h2 etc)
• keyword optimised but not spammy/stuffy (for deeper pages consider long tail kewords)
• Short, descriptive and engaging text*

*for example mission statements should say who the website represents, what they do and why they're special. Ideally in less than 20 words; think snappy newspaper headline. Answer user intent!